NIST DCE Report - R2 _3_.pdf

Decontamination and Decommissioning Cost Estimate

National Institutes of Standards and Technology

Gaithersburg, MD

Revision 2

Prepared by:

Philotechnics, Ltd.

201 Renovare Blvd.

Oak Ridge, TN 37830

August 2009

License No. SNM-0362 August, 2009 Revision 2

National Institutes of Standards and Technology Gaithersburg, MD Facilities D&D Cost Estimate

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TABLE OF CONTENTS

1.0 Executive Summary

2.0 Objectives

3.0 Process

4.0 General Assumptions

4.1 Radioactive Waste Materials

4.2 Sealed Sources

4.3 Unsealed Sources

4.4 Labor Estimates

5.0 Release Criteria

6.0 Review of Previous Clearance Surveys

7.0 Decommissioning Process and Cost Estimate Details

7.1 Tab 3.5, Detailed Descriptions of Facilities and Equipment

7.2 Tab 3.6, Planning and Preparation

7.3 Tab 3.7, Decontamination or Dismantling of Radioactive Facility Components

7.4 Tab 3.8, Restoration of Contaminated Areas

7.5 Tab 3.9, Final Radiation Survey

7.6 Tab 3.10, Site Stabilization and Long-Term surveillance

7.7 Tab 3.11, Total Days by Labor Category

7.8 Tab 3.12, Worker Unit Cost Schedule

7.9 Tab 3.13, Total Labor Costs by Major Decommissioning Task

7.10 Tab 3.14, Packaging, Shipping, and Disposal of Radioactive Wastes

7.11 Tab 3.15, Equipment Supply Costs (excluding containers)

7.12 Tab 3.16, Laboratory Costs

7.13 Tab 3.17, Miscellaneous Costs

8.0 Periodic Updates to Decommissioning Cost Estimate

TABLE OF APPENDICES

Appendix A – Accelerator Radiological Scoping Reports

Appendix B – Facility Laboratory Cost Estimating Worksheets Appendix C – Accelerator Component and Area Cost Estimating Worksheets

Appendix D – Sealed Source Inventory for Disposal

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ACRONYM LIST

ALARA As Low As Reasonably Achievable CFR Code of Federal Regulations D&D Decontamination and Decommissioning DCGLEMC Derived Concentration Guideline Level – Elevated Measurement Comparison DCGLW Derived Concentration Guideline Level – Wilcoxon Rank Sum DOE United States Department of Energy DQO Data Quality Objective DSV Default Screening Value HSA Historical Site Assessment HVAC Heating , Ventilation, Air Conditioning MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual MDC Minimum Detectable Concentration NMSS Nuclear Materials Safety and Safeguards NRC U.S. Nuclear Regulatory Commission NUREG Nuclear Regulatory Commission Guidance Document QAPP Quality Assurance Project Plan RSO Radiation Safety Officer RSC Radiation Safety Committee TEDE Total Effective Dose Equivalent

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1.0 Executive Summary

The National Institute of Standards and Technology (NIST) headquartered in Gaithersburg, Maryland, contracted Philotechnics, Ltd. to develop facility decommissioning cost estimates (DCE) for their non-reactor radiological facilities in Gaithersburg. Such facilities include particle accelerators and laboratories operated under U.S. NRC License No. SNM-0362. Per NIST’s request, Philotechnics developed detailed “bottom-up” cost estimates based on review of facility design features, current and historical radionuclide use, present radiological conditions and physical waste inventory. Philotechnics also evaluated Decontamination and Decommissioning (D&D) work approaches and task sequences in order to estimate labor, materials and supplies.

This report describes the overall process applied to developing the cost estimate, the general assumptions regarding facility D&D, general assumptions regarding radioactive waste processing and disposal, and specific assumptions and calculations with respect to this facility. Included in the report are abbreviated Decommissioning Plans for laboratories and accelerator facilities.

Laboratory facilities are expected to be completely decontaminated and remediated. This work will consist of removing all radioactive material, decontamination of contaminated building surfaces, and remediation or removal of volumetrically-contaminated materials. Laboratory facilities will then be surveyed and released for unrestricted use in accordance with NUREG 1575, Multi-Agency Radiation Site Survey and Investigation Manual (MARSSIM), Radioactive accelerator components, waste, and non-structural material will be removed and disposed of as radioactive waste. Accelerator facilities contain activated structural material that cannot be safely removed without demolishing the entire building, which in most cases consists of several stories. Such activities would be extremely costly and would subject personnel to unnecessary risks during the decommissioning process. Furthermore, the NIST property is U.S.

Government owned and is expected to remain long after the facility is decommissioned. For those reasons, a limited release followed by long-term monitoring is the preferred avenue for estimation of decommissioning costs.

Cost estimates were developed using conservative “middle of the road” assumptions regarding likely extent and duration of remediation activities. Remediation was assumed to proceed to levels suitable for unrestricted release of the site. Cost estimates were prepared in accordance with and in the format of NUREG 1757 “Consolidated NMSS Decommissioning Guidance” Volume 3. Per NUREG 1757, a contingency of 25% is required to be added to decommissioning estimates to address unidentified and unanticipated conditions. The overall estimate for the Gaithersburg facility is:

Table 1.1 – NIST Gaithersburg, MD Facilities Overall D&D Cost Estimate

Estimate 25% Subtotal Laboratory

Areas $2,615,180 $653,795 $3,268,975

Accelerator Areas $1,777,763 $444,440 $2,222,204

TOTAL $4,392,943 $1,098,235 $5,491,178

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In accordance with 10 CFR 30.35, this decommissioning plan should be evaluated in 3 years and revised to account for any changes in the costs required for decommissioning activities.

This report describes the thought process and methodologies used to estimate decommissioning costs. Cost estimate details are included in the attached spreadsheets included as appendices.

Additionally, a scoping survey was conducted in the accelerator spaces; that report is also included as Appendix A.

Nothing in this document should be construed as binding at the time of final decommissioning.

The survey methods, release limits, radionuclides of concern, and facility configurations described are based on conditions observed during the site visit, historical documentation, sample analysis, and professional opinion as to the process of the final decommissioning and survey.

2.0 Objectives

The principal objectives of this analysis are to: 1) develop reliable estimated total facility decommissioning costs for NIST’s Gaithersburg operations, 2) provide a documented inventory of facility features and characteristics, and, 3) describe the steps that will need to be taken to effect complete decommissioning of the site.

3.0 Process

A schedule of equipment, features and characteristics was developed to capture the size of each space and key features relevant to developing decommissioning cost estimates. Specifically, facility floor plans were reviewed, and the principle features and equipment of each laboratory were inventoried and categorized.

Each active laboratory was inspected, and radiation and contamination surveys were reviewed. In most laboratories, direct contamination measurements were impossible due to the presence of radioactive materials; NIST management advised us to use existing routine contamination surveys to determine the likely extent of contamination in laboratory areas. The radioactive materials database was reviewed to determine the radionuclides of concern in each area.

Samples of structural materials and shielding were collected in spaces affected by accelerator operation to determine the radionuclides present and estimate the extent of activation. Historical records were reviewed including the radioactive materials license, previous DCEs, and laboratory closure surveys. NIST management was consulted regarding past and present operations and their effect on future decommissioning.

The work scope and activity sequence to support license termination were developed. Cost estimates for projects were based on anticipated Time and Materials rates for goods, labor and services necessary to complete each project. It became clear that unrestricted release of accelerator facilities would be expensive and dangerous work, because many of those areas are activated throughout the volume of structural materials and possibly into the soil. Some of those areas are below the water table, rendering safe handling of radioactive material and control of the spread of radioactivity virtually impossible while those structures are being dismantled and removed. For those reasons, after consultation with NRC personnel, it was decided to pursue restricted release combined with long-term surveillance for those areas.

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Labor estimates were derived from the work scope and a project plan outline. A project plan outline was developed for each facility detailing the sequence of tasks required to decommission the facility and terminate its radioactive material license. An overall project schedule was estimated that considered work to be performed, material flow paths, optimal number of crews and crew size and constraints (i.e., bottlenecks) in the D&D process. Crew sizes and task durations were estimated based on the numbers and locations of tasks to be performed.

Marketplace rates were obtained for each element of the project including project labor, materials, supplies, sampling and waste packaging, processing and disposal. NUREG 1757 requires the cost estimate to assume an out-of-state contractor performs the work; therefore nationwide mean salaries for the appropriate labor categories were used based on the latest available data from the U.S. Department of Labor, Bureau of labor Statistics. The unit rates were extended through the estimated quantities to determine total cost for each line item. Costs were summed by each element of the project to determine sub-total by element. Element sub-totals were summed to total project cost.

Radioactive waste estimates were based upon the volume of material in the laboratories storage areas and supporting systems. For D&D purposes, contaminated equipment was assumed to be disposed of as radioactive waste rather than being decontaminated and released. This is due to the cost of labor required to decontaminate and survey equipment typically exceeding the cost of disposal. Material that is not likely to be contaminated above release limits is assumed to be surveyed for unconditional release in accordance with Regulatory Guide 1.86. Activated shielding, structural material and equipment, and debris from remediation of contaminated surfaces will be handled and disposed of as radioactive waste.

4.0 General Assumptions

Overall, “middle of the road” assumptions were made concerning the likely extent and duration of necessary remedial activities. For laboratories, remediation to unrestricted levels (i.e., the facility could be released for any future use without restrictions) was assumed, meaning there are no long term costs associated with site surveillance and monitoring following decommissioning.

Some accelerator facilities will require surveillance and monitoring after license termination as discussed later. It is assumed decommissioning activities will begin within a few months after accelerator operations cease such that short-lived activation products will have decayed to negligible levels.

4.1 Radioactive Waste Materials

In developing estimates of volume of radioactive waste, overall outside dimensions were used for equipment, components and furnishings. These overall volumes were assumed to be size reduced somewhat on site, so they were multiplied by an average density of 15 lb/ft3 (DAW) and 20 lb/ft3 (metal) to determine the total mass of waste. For example a standard office desk would be estimated as 5 ft. wide by 2.5 ft. deep and 2.5 ft. tall with an overall volume of 31.25 ft3 and an estimated mass of 470 lbs. A waste fraction was then applied based on the anticipated percentage of equipment expected to be contaminated. Consumables used in the D&D process showed up in waste estimates under Dry Active Waste (DAW).

The accelerators and directly affected equipment such as targets, beam dumps, and shielding are assumed to be radioactive and will be disposed as radioactive waste.

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Ventilation system waste estimates were based on dimensions of components. Ventilation up to and including the HEPA filters is considered in this report.

Waste mass is multiplied by marketplace rates for waste processing and disposal. Packaging and transportation costs were estimated by volume and were added to the total waste disposal figure.

Potential overestimates of component volumes as a result of using overall dimensions were offset by smaller pieces of equipment that were not individually estimated. Actual volume of waste expected to be removed from the site was considered in the cost estimate. No credit was given for reuse at other facilities or possible resale value. Waste processing activities were assumed to take place at a licensed facility in Tennessee, with a one way travel distance of 525 miles.

4.2 Sealed Sources

According to the Health Physics database, NIST possesses approximately 373 sealed or encapsulated sources that will need to be packaged and shipped for disposal or storage. Appendix D contains a list of the current sources at the facilities along with their activity and location at the site.

Since the closure of Barnwell, no disposal option exists for many sources. NIST is critical to the success of a technological society and it is difficult to imagine a scenario whereby it is completely eliminated. Decommissioning of the Gaithersburg site would most likely be associated with construction of a new facility elsewhere and most sources would be moved and put into service in the new facility. Still, complete decommissioning and disposal of all sources remains a remote possibility and some cost should be attributed to it. Rather than itemize individual sources and weigh hypothetical transfer/disposal/storage options, we will assume for now that sealed sources will be transferred to the U.S. Department of Energy. Discussions with DOE personnel indicated $500,000 may be reasonable. The sources will be shipped as a Type B shipment to Nevada, a distance of 2400 miles. Additional costs are $100,000 for a Type B package and shielding, $84,000 for transportation to Nevada, and $60,000 for security and administration of Increased Controls at NIST during the decommissioning project.

Only sources belonging to NIST and having activity greater than 1 μCi are considered here.

Sources belonging to other licensees will be returned to them. Sources less than or equal to 1 μCi will be included with other waste and shipped to a waste processor for treatment and/or disposal.

4.3 Unsealed Sources

The health physics database was used to estimate the amount of radioactive material in the form on unsealed sources on site. The total activity of those sources is approximately 370 mCi. This material can be mixed with other low level waste for disposal. Only sources belonging to NIST are included in this estimate; it is assumed all other sources will be returned to the customer.

4.4 Labor Estimates

All labor estimates are expressed in workdays. Workdays are actual days on the job. Project schedules were based on 5-day workweeks excluding weekends, holidays, etc., consisting of 8 hours per day.

Labor estimates for Planning and Preparation include time for document preparation, decommissioning plan submittal to regulatory agencies, work plan development, equipment procurement, staff training and mobilization. Pre-planning labor estimates assume

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National Institutes of Standards and Technology straightforward internal and external document, plan and procedure reviews and approvals. The duration of field activities for decontaminating and dismantling the facilities were estimated based on the task sequence and project schedule.

Crew sizes and number of workers were limited to those that could be efficiently utilized in the field. The size of the work force size will vary. At its peak, it is assumed to consist of one Project Manager directing the activities of two crews. Each crew will consist of one Supervisor;

two Health Physics Technicians; four Skilled Craftsmen, and four Unskilled Laborers.

Additionally, one shipper and one administrative assistant will report directly to the Project Manager.

The duration of activities for remediation of facilities and grounds was based on the expected level of remediation that would be required to return the facility to unrestricted release conditions.

Similarly, estimates for the level of effort required for the final radiation survey were based on previous experience with facilities of comparable complexity. As noted above the assumed endpoint is license termination and unrestricted release of the facility; consequently, long term stabilization and monitoring is not required and no costs are incurred for this element.

Annual labor rates were estimated for the project manager, a project supervisor, a health physicist, a shipper, health physics technicians, radiation workers and administrative support.

Labor rates included base salary and fringe benefits (e.g., vacation, health insurance, etc.). A rate of 75% was applied for overhead costs. The base annual labor rate plus the overhead expenses was divided by the number of workdays per year (taken as 260) to determine a daily cost for each category of employee.

Living expenses were taken from allowable government per diem rates – $273 per day for Montgomery County, MD. Project management, supervision and technical staff are paid the daily living allowance since they are assumed to be from outside the local area. Radiation workers (laborers) and administrative support staff were assumed to be local hires and are not paid a living allowance. The daily living expenses were multiplied by 7 days per week then divided by 5 workdays per week to correctly incorporate living expenses into the daily wage rate.

5.0 Release Criteria

The ultimate release criteria is specified in 10 CFR 20.1402: “A site will be considered acceptable for unrestricted use if the residual radioactivity that is distinguishable from background radiation results in a TEDE to an average member of the critical group that does not exceed 25 mrem (0.25 mSv) per year, including that from groundwater sources of drinking water, and the residual radioactivity has been reduced to levels that are as low as reasonably achievable (ALARA).

Determination of the levels which are ALARA must take into account consideration of any detriments, such as deaths from transportation accidents, expected to potentially result from decontamination and waste disposal.”

For the NIST facilities in Gaithersburg, it is assumed the buildings will be reused for some other, as yet unknown, purpose. The occupant will have unrestricted access. Pathways applicable to such an occupant include external dose, inhalation, soil ingestion, and drinking water from radioactivity that migrates to ground water.

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Tools, materials, and removable equipment will be surveyed for unconditional release as applicable using the guidance contained in Regulatory Guide 1.86 for the radionuclides of concern.

Building surfaces and installed equipment will be surveyed using the guidance contained in NUREG 1575, Multi-Agency Radiological Site Survey and Investigation Manual (MARSSIM).

Areas adjacent to one another having similar radiological characteristics will be grouped together as applicable into survey units. Contamination release limits will be derived from a number of sources. For planning purposes, the radionuclide know to be present or shown in the database as having been used that is associated with the lowest release limit will be used according to the following guidance:

• Default screening values listed in NUREG 1757, Appendix B, are used where they are listed.

• For radionuclides not listed in NUREG 1757, the release limit will be derived using the NRC DandD Ver. 2.1 software code default parameters.

• At the time of actual decommissioning and License termination, future site usage may be more stringent; in that case the RESRAD family of codes may be used.

Actual radionuclides of concern and the relative abundance of each will be determined early in decommissioning, during the characterization phase; that process will yield accurate derived concentration guideline limits (DCGLs). Therefore, the limits derived in support of this DCE are thought to be quite conservative.

In this DCE, the following values are limiting, assuming no more than ten percent of the total activity is removable:

Table 5.1 – Limiting Radionuclides

Radionuclide(s) Default Screening Value (dpm/100 cm2) Basis

Beta-gamma emitters except H-3 and C-14 7,100 Co-60

Transuranics 23 Am-241 Uranium 88 U-238

H-3 1.2E+07 10% of screening value C-14 3.7E+06 Screening value

For activated building components, the major dose pathway is external exposure from gamma emitting radionuclides. Default screening values for contaminated surface soil listed in NUREG 1757, Appendix B are used. They are:

Table 5.2 – Surface Soils DSVs

Radionuclide DSV pCi/g

Co-60 3.8 Eu-152 8.7

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National Institutes of Standards and Technology Gaithersburg, MD Facilities D&D Cost Estimate

6.0 Review of Previous Clearance Surveys

Surveys supporting clearance of several rooms from radiological controls were reviewed as shown below:

Table 6.1 – Previously Cleared Laboratories or Rooms Building Room(s)

218 C002 245 C112; C115; B030; C201; B009; B024; C334; B01; C133; B133;

C116 224 A114 222 A206; A110; A116; A122; A128; A132; A148; B125; B126 221 A41

In general, surveys appear to indicate no residual radioactive material is likely to be present;

however documentation lacks sufficient detail to make that determination with certainty. For instance:

• Dose rate surveys indicate radiation dose rates are at or near ambient levels.

• Results of direct measurements for total contamination are not routinely recorded.

• Smears are counted for gross alpha and beta; however results are reported in units of net cpm. Instrument efficiency is not shown on the survey. Each page bears a statement in bold type that reads, “≤20 dpm/100 cm2 Alpha and ≤1000 dpm/100 cm2 Beta/Gamma removable unless noted.”

Residual contamination levels in those labs may in fact be less than the DCGL that would be in effect today based on usage; however in the event of license termination, some follow-up surveys would need to be performed.

• Room 222/A122 contained natural and depleted uranium and thorium. The DCGL for depleted uranium is in the neighborhood of 88 dpm/100 cm2 total contamination, assuming less than 10% is removable. It is not clear from reviewing the clearance survey that the DCGL would be met.

• Rooms 222/A132 and 245/C133 contained Pu-238. The DCGL for that radionuclide is approximately 24 dpm/100 cm2 total contamination, assuming less than 10% is removable. It is not clear from reviewing the clearance survey that the DCGL would be met.

Philotechnics believes laboratories previously released from radiological controls will require some type of follow-up survey, described in following sections. Many previously-used rooms have been completely gutted and remodeled; others are now offices; still others had adjoined other radiological laboratories and the wall separating them was removed. Rather than list every previously-used room individually; time and resources are allotted to performing follow-up surveys in all previously-used rooms as a group.

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National Institutes of Standards and Technology Gaithersburg, MD Facilities D&D Cost Estimate

7.0 Decommissioning Process and Cost Estimate Details

The work crew consists of:

• Project Manager (1)

• Project Supervisor (2)

• Shipper (1)

• Health Physics Technicians (4)

• Skilled Laborers (2)

• Unskilled Laborers (2)

• Administrative Assistant (1)

The time required to complete the project is approximately 150 days on site: 90 days for the laboratories and 60 for the accelerators. This is less than the maximum limit of 180 days per calendar year to work under reciprocity with the U.S. NRC. Therefore, one reciprocity fee of $1400 will cover both aspects of the work.

Following is a description of the assumptions made and data entered into individual worksheets to calculate the potential cost of decommissioning. Two sets of spreadsheets were developed for this cost estimate. One set of spreadsheets pertains to laboratory areas and the other to the accelerator areas. The spreadsheets pertaining to the laboratories are provided in Appendix B and the spreadsheets for the accelerator areas are provided in Appendix C.

7.1 Tab 3.5, Detailed Descriptions of Facilities and Equipment For clarity, this worksheet was split up into multiple parts, each labeled by building number.

Accelerator facilities and associated equipment, housed in Building 245, are attached.

In addition to the accelerators, Building 245 also houses most of the active radiological laboratories.

Laboratories vary in size, configuration, materials, and equipment according to their function.

Each individual laboratory that was inventoried for this DCE is listed in Tab 3.5. The inventory lists, as a minimum, room dimensions, amount of furnishings and equipment used and stored in the room, the radionuclide(s) currently or previously used, and the expected MARSSIM class based on current use and survey data.

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Initial assignment of MARSSIM class for final status surveys is as follows:

Table 7.1 – Previously Cleared Laboratories or Rooms

CLASS 1 • Current use of unsealed material

• Current or previous use of neutron sources

• Areas adjacent to accelerators

• Areas with uncertain history

• Some remediation may be expected

• Some radwaste may be expected – fraction inversely proportional to release limit.

• Accelerator facilities will have a lot of radwaste

• Some rooms are not listed in the database as ever having radioactive materials – so if we don’t know what was used, we assume the worst.

CLASS 2 • Accelerator support areas separated by shielding

• Previous use of unsealed TRU, U, Ra, or Th sources and clearance surveys were done (many have been gutted and remodeled).

• Verification that materials are not activated or contaminated

• Removable contamination surveys previously performed cannot detect alpha emitters below DCGL

• No remediation is expected

• No radwaste (except sources) is expected.

CLASS 3 • Current use of sealed beta, gamma or alpha sources

• Previous use of unsealed beta-gamma sources but clearance surveys were done

• Restrooms and hallways “upstream” of personnel contamination monitors.

• No history of leaking sources.

• Removable contamination surveys previously performed should detect most beta-gamma emitters.

• No remediation is expected

• No radwaste (except sources) is expected

There are approximately 100 previously-used rooms not specifically listed in the inventory.

Average dimensions of 20 feet by 25 feet with 15-foot ceilings. They are assumed to be 50% Class 2 and 50% Class 3.

7.2 Tab 3.6, Planning and Preparation

This tab includes such tasks as filing for reciprocity to conduct the decommissioning, preparation of work plans including the Decommissioning Plan, site-specific training for workers, and mobilization to the site. The Project Manager develops work plans and submits reciprocity applications. The laborers and administrative assistant are assumed to be local hires and no time is required for mobilization; the other workers need a full day to mobilize to the site. The Project Manager also must secure a contract for a crane and crew.

This tab also includes facility characterization. Characterization is performed to determine the radionuclides present in each area and the extent of contamination. Health physics technicians will enter each area where radioactive materials have been used, collect samples, scan surfaces, segregate potentially radioactive material from non radioactive, and identify any mixed waste.

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In most cases, the health physics database maintained by NIST identifies current and historical use of radionuclides in each room. The time estimated to characterize the room is based on that information. For instance: if a room contained transuranics, uranium, radium, beta-gamma emitters and I-129, the room will be scanned three times. A beta-gamma probe (floor monitor for large floor areas and BP19 or equivalent for other surfaces will be used to measure contamination from most beta-gamma emitters. An alpha-sensitive probe will be used to measure contamination from alpha emitters. A very slow scan rate of only an inch or so per second is required. Finally, a probe sensitive to gamma and very low energy beta emitters (such as the GP-13 or equivalent) will be used to measure contamination from I-129, Co-57, and similar difficult-to-detect radionuclides. Smears will be collected and counted for gross alpha and gross beta and analyzed on a liquid scintillation counter. Samples will be sent to an independent laboratory for radionuclide identification. These assumptions will also apply to Tabs 3.7 and 3.9.

7.3 Tab 3.7, Decontamination or Dismantling of Radioactive Facility Components This tab includes removal and packaging of radioactive material such as contaminated equipment and preparation for transport to a licensed processor or disposal facility. Most material is neither contaminated nor activated and will be surveyed for unconditional release. Labor hours are allotted for those unconditional release surveys as well as to move, remove, and break down equipment as necessary to facilitate release surveys or make areas accessible for MARSSIM surveys.

The order in which various buildings will be decommissioned is unknown; however, in Building 245, laboratory areas will be decontaminated and decommissioned before accelerator facilities for a number of reasons: accelerators contain short-lived byproduct material and delaying work allows for some decay; most accelerator spaces are below laboratory spaces and it makes sense to start at upper floors and work down; laboratories will be fully decontaminated and remediated while some accelerator spaces will be locked shut and subject to long-term surveillance.

7.4 Tab 3.8, Restoration of Contaminated Areas

Based on existing survey data, surface scans performed during the site visit, and interviews with knowledgeable individuals, very few laboratory areas will require any remediation.

Accelerator facilities (described separately) will require extensive remediation of floor, walls, equipment, and structural materials. The Time of Flight Facility is above grade and remediation efforts will result in partial demolition of the building. Other activated accelerator spaces are below grade. Many are below the water table, such that demolition of those structures would increase the likelihood of releasing radioactive materials to the environment. Many of the most highly activated areas are load-bearing or exterior walls. Complete remediation would therefore require complete demolition of all of Building 245 – a costly endeavor. For reasons of cost reduction, worker safety and protection of the environment, those areas will be remediated to the extent practicable and then re-evaluated. It is assumed the sub basements containing those accelerators will be secured, and long-term monitoring instituted, until activation products decay to levels acceptable for unconditional release.

7.5 Tab 3.9, Final Radiation Survey

The final radiation survey is performed by health physics technicians, with guidance from the project manager and project supervisors and administrative support. In cases where no

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7.6 Tab 3.10, Site Stabilization and Long-Term surveillance

Because the goal is unconditional release of the laboratory facilities, there are no long-term surveillance requirements associated with them.

7.7 Tab 3.11, Total Days by Labor Category

This is the sum of person-days listed in Tabs 3.6 through 3.10.

7.8 Tab 3.12, Worker Unit Cost Schedule

Worker mean nationwide salaries are taken from the Bureau of Labor Statistics and are adjusted to account for the cost of fringe benefits. A 75% multiplier is also added to account for profit to the contractor performing the decommissioning work. Workers who are not local hires are paid the government per diem rate of $273 daily for the Gaithersburg area.

7.9 Tab 3.13, Total Labor Costs by Major Decommissioning Task This tab shows the cost of each major task from Tabs 3.6 through 3.10 multiplied by the daily labor cost for each worker shown in Tab 3.12

7.10 Tab 3.14, Packaging, Shipping, and Disposal of Radioactive Wastes This tab reflects the most costly component of the facility decommissioning. It is assumed waste is shipped to a licensed waste processor in Oak Ridge, Tennessee, a distance of approximately 600 miles.

7.11 Tab 3.15, Equipment Supply Costs (excluding containers)

This tab shows the approximate costs of personnel protective clothing and respirators, rental of specialty equipment including health physics survey instruments, and consumables required to complete the decommissioning.

It is assumed a crane and crew will be needed for removal of accelerators and large equipment.

Other equipment includes health physics survey instrumentation, concrete cutters, jack hammers, containment structures, vacuum cleaners, negative ventilation systems, nibblers, and shears.

7.12 Tab 3.16, Laboratory Costs

This tab shows the total of all samples to be collected and sent out for analysis as shown in the various subsections of Tab 3.5. It is assumed all samples will be analyzed for gamma emitters, Sr-90, H-3, C-14, and alpha emitters such as uranium, plutonium, and americium isotopes.

Samples collected from accelerator facilities will be analyzed for gamma emitters.

7.13 Tab 3.17, Miscellaneous Costs

This tab shows other costs not specifically captured elsewhere. It is assumed the decommissioning contractor will perform the work under reciprocity agreement with the U.S.

NRC at a cost of $1400. Liability insurance and state/local taxes are included at the rate of 6 percent and 10 percent, respectively, of the on-site labor costs.

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National Institutes of Standards and Technology Gaithersburg, MD Facilities D&D Cost Estimate

8.0 Periodic Updates to Decommissioning Cost Estimate

This cost estimate was prepared using the tables and instructions provided in NUREG 1757.

Tables were converted to Excel spreadsheets and modified as necessary to enhance their applicability to the NIST site and to facilitate updating costs in the future. As areas are decommissioned from radiological use or new areas are added, that information may be changed in the spreadsheet. Labor and per diem rates are likely to change in the future. That information may be updated in Tab 3.12 to reflect future labor costs. Transportation costs including mileage, fuel surcharges, overweight/oversize charges; costs of shipping containers; and disposal, site access and license costs may be updated by inserting applicable values into Tab 3.14.

For reference, the table below shows expected escalation of decommissioning costs over the next 20 years. The annual escalation rate was estimated as the average annual United States rate of inflation between 1946 (the first full year after World War II) and 2008 according to the U.S.

Consumer Price Index. That rate is 4.1 percent.

Year Escalation

Factor Laboratory

Areas Accelerator

Areas 25%

Contingency TOTAL 2009 --- $2,615,180 $1,777,763 $1,098,236 $5,491,179 2010 0.041 $2,722,402 $1,850,651 $1,143,263 $5,716,317 2011 0.041 $2,834,021 $1,926,528 $1,190,137 $5,950,686 2012 0.041 $2,950,216 $2,005,516 $1,238,933 $6,194,664 2013 0.041 $3,071,175 $2,087,742 $1,289,729 $6,448,645 2014 0.041 $3,197,093 $2,173,339 $1,342,608 $6,713,040 2015 0.041 $3,328,174 $2,262,446 $1,397,655 $6,988,275 2016 0.041 $3,464,629 $2,355,206 $1,454,959 $7,274,794 2017 0.041 $3,606,678 $2,451,770 $1,514,612 $7,573,060 2018 0.041 $3,754,552 $2,552,292 $1,576,711 $7,883,556 2019 0.041 $3,908,489 $2,656,936 $1,641,356 $8,206,782 2020 0.041 $4,068,737 $2,765,871 $1,708,652 $8,543,260 2021 0.041 $4,235,555 $2,879,271 $1,778,707 $8,893,533 2022 0.041 $4,409,213 $2,997,322 $1,851,634 $9,258,168 2023 0.041 $4,589,991 $3,120,212 $1,927,551 $9,637,753 2024 0.041 $4,778,180 $3,248,140 $2,006,580 $10,032,901 2025 0.041 $4,974,086 $3,381,314 $2,088,850 $10,444,250 2026 0.041 $5,178,023 $3,519,948 $2,174,493 $10,872,464 2027 0.041 $5,390,322 $3,664,266 $2,263,647 $11,318,235 2028 0.041 $5,611,325 $3,814,501 $2,356,457 $11,782,283 2029 0.041 $5,841,390 $3,970,895 $2,453,071 $12,265,356

Appendix A Accelerator Radiological Scoping Report

Radiological Scoping Report

Prepared for:

National Institute for Standards and Technology Radiation Physics Building Gaithersburg, MD 20899

Survey Dates: March 23 - 27, 2009 Report Date: May 21, 2009

Prepared by:

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Radiological Scoping Report

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P: 865.483.1551 F: 865.220.0686

Section 1.0 Executive Summary

A scoping survey was performed the Radiation Physics building located at the National Institute of Standards and Technology (NIST) where linear accelerators (LINACS) currently or have historically been in operation. The survey was limited to accelerators which have enough energy to create free neutrons (>8 MV). The purpose of the survey was to determine if any of the facility structures had become neutron activated as a result of the LINAC operation and to provide a cost estimate to remediate any activated areas to unrestricted levels. The project was performed to aid in the writing of the decommissioning funding plan which is required under 10 CFR 30.35 “Financial Assurance and Recordkeeping for Decommissioning”.

Core samples were collected throughout the facility and sent to an offsite laboratory for gamma spectroscopy analysis. The sample locations were chosen based on two criteria: areas where elevated readings were detected using the hand-held equipment and professional judgment of the Project Manager. As a general rule, judgmental samples were taken on structures near beam targets, beam dumps and any areas where the beam made a directional change.

A total of 23 volumetric samples were collected and sent to a NVLAP accredited laboratory to be analyzed via gamma spectroscopy. In areas where elevated readings were found, samples were collected from two sampling depths (0 to 6 inches and 6 to 12 inches). In areas where elevated readings were not found, only one core sample was taken from 0 to 6 inches. The results of the two sampling depths will be used to estimate the amount of remediation that will be required to bring the areas below unrestricted release levels. At the time of the survey, the unrestricted release limits were based on a total effective dose equivalent of 25 mrem/yr.

Section 2.0 Scoping Survey Radiological surveys were conducted using a Canberra portable multi-channel analyzer with a lanthium bromide (LaBr) probe for nuclide identification and a 100 cm2 cesium iodide (CsI) hand-held gamma probe connected to a Ludlum 2350-1 survey meter. The gamma probe was selected because the typical activation products (Co-60, Eu-152 and Eu-154) all have gamma emissions which are easily detectable.

Ten (10) one-minute background readings were collected in non-impacted areas of the basement and sub-basement with similar construction materials to the areas being surveyed. The average of the backgrounds counts was calculated and used for purposes of background subtraction.

Using a scan rate of 5 cm/sec, the entire tunnel was surveyed, any areas which showed elevated readings were marked and a static measurement was performed. Volumetric samples were taken at the areas with the highest static readings.

Initially we planned on collecting the core samples using a rotary hammer with a 2 inch dry coring bit; however, the concrete was too dense to penetrate. We switched to a chiseling bit and this was effective for the 0 to 6 inch sample. For the 6 to 12 inch sample, a concrete drill bit was used. One benefit of using the chiseling and drill bits is the material collected was a homogenized fine powder and no additional preparation was necessary before sending the sample in for analysis.

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The following paragraphs discuss areas in the Radiation Physics building that were surveyed looking for activated components. These areas include: the previously decommissioned 100 MeV linear accelerator tunnel, the Magnet and Measuring rooms, the Medical Industrial Radiation Facility (MIRF), the CLINAC room and the Time of Flight Facility. These areas were chosen because of their potential for neutron activated components.

100 MeV Linear Accelerator Tunnel The first area surveyed was the previously decommissioned linear accelerator (LINAC) tunnel which housed a 100 MeV accelerator. The tunnel is located in the sub-basement of the Radiation Physics building and is approximately 156 feet long by 9 feet wide. The scan survey was initiated using the gamma probe at the particle source and continued down the tunnel to a concrete wall which was erected after the accelerator was removed. On the other side of the wall are the Measurement and Magnet Rooms which were surveyed separately.

After scanning was completed, four (4) sample locations were selected where elevated readings were detected and two (2) core samples were collected at each location (0 to 6 inches, 6 to 12 inches). It is important to note that all core samples were from the walls of the tunnel; the sub-basement is below the water table and core samples were not collected on the floor to prevent possible flooding from ground water.

The first set of core samples were collected adjacent to the newly erected concrete wall. Using both the chiseling and drill bit, approximately 2000 grams of material was collected from each core depth. Three additional sample locations in the tunnel were chosen based on elevated readings noted during the scan survey. A scaled drawing of LINAC tunnel is attached as Appendix A detailing where the core samples were collected.

Magnet Room and Hallway The concrete wall separates the LINAC tunnel from the Magnet room and Measurement rooms 1 & 3. After the wall, the accelerator beam had the option of being diverted 3 directions; either to one of the two Magnet rooms that are perpendicular to the beam line or at a 45 degree angle to where the MIRF facility is currently housed. A total of 5 volumetric sample locations were selected based on elevated static readings and professional judgment. Three of the locations had elevated readings and core samples were collected at two depths (0” to 6”, 6” to 12”). The other two core sample locations were chosen due to the potential for activation; one at the beam dump and the other where the beam was re-directed to Measurement Room #3. No elevated readings were detected with the hand-held meters so the core samples were only taken from 0 to 6 inches in order to confirm that no activation was present.

Medical Industrial Radiation Facility The Medical Industrial Radiation Facility (MIRF) currently houses a high energy electron beam accelerator which can produce energies from 7 million to 32 million electron volts (MeV). It is ideally suited for medical radiation calibration research and industrial radiation technology department. The facility is currently located in the space where Measurement Room 2 for the 100 MeV LINAC used to occupy. The facility is rectangular in shape, approximately 45 feet long and 38 feet wide and at one time was the location of the beam stop. The MIRF accelerator

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was in use on a daily basis which made it difficult to scan due to activated components from the beam line. Static measurements were performed along the perimeter walls of the facility which were far enough from the beam to avoid any contribution from the activated beam line. One volumetric sample (0” to 6”) was collected at the end of the former beam dump tunnel.

CLINAC Room The CLINAC room houses a 6 MeV to 20 MeV electron-beam (6 MV and 18 MV bremsstrahlung beam) Varian Clinac 2100C to support the development of direct, therapy-level dosimetry calibrations. The square room (30’ x 30’) was scanned and static measurements were taken. It was determined that no volumetric samples would be collected due to all the static measurements being below 5,000 dpm/100 cm2.

Time of Flight Facility The Time of Flight Facility (TOFF) was previously used to calculate neutron capture cross sections for a variety of different radionuclides. Elevated readings were noticed immediately upon entering the facility ranging from 40,000 to 200,000 cpm/100 cm2. Volumetric samples were taken at the two highest static reading locations. There is a pit inside the room where the neutron beam entered the room from the basement and a third sample location was selected in the pit at the highest static reading location.

Positive Ion Van de Graaff Generator A Van de Graaff generator is an electrostatic machine which uses a moving belt to accumulate very high electrostatically stable voltages on a hollow metal globe. The potential differences achieved at the Van de Graaff generator located in the basement, room 26, can reach 3 MV’s. A scan survey using the hand-held gamma meter was performed on all structural surfaces in the room. No elevated readings exceed in the DCGLw were found and the decision was made not to collect any volumetric samples. Based on the hand-held readings, the room meets the release criteria for unrestricted use and no remediation is necessary.

1.5 MeV Dynamitron

The Dynamitron is a dc beam accelerator capable of producing electrons or hundreds of microamps of positive ions from 0.2 to 1.5 MeV. The Dynamitron located in rooms B21, B22 and B23 was scan surveyed using the hand-held gamma meter. No elevated readings exceed in the DCGLw were found and the decision was made not to collect any volumetric samples.

Based on the hand-held readings, the room meets the release criteria for unrestricted use and no remediation is necessary.

SURF III Synchrotron

The SURF III Synchrotron Ultraviolet Radiation Facility is the world's senior dedicated source of synchrotron radiation, in continuous operation since 1961. Synchrotron radiation is the light emitted by electrons as they are propelled around a donut-shaped ring in a strong magnetic field.

The light emitted from SURF III covers the infrared, visible, ultraviolet and extends into the X-ray region of the electromagnetic spectrum. It is exceptionally pure, and scientists can tune it to a desired wavelength to probe and measure a wide variety of materials and devices.

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The maximum energy that electrons are accelerated to in the storage ring is 400 MeV. At injection, the electrons are accelerated to 10 MeV using a Microtron system and then extracted and injected into the storage ring. At injection, 2 micro-second pulses of 10 MeV electrons are sent into the ring at a repetition rate of 7.5 Hz, with an average current of up to 80 mA. Once the injection parameters are optimized, the Microtron injection is stopped and the captured electrons are ramped up in energy. The normal operating energy is 380 MeV and one beam normally lasts for 7 hours which is the time it takes for the beam to decay from 300 mA to 150 mA. The remaining 150 mA is usually dumped and the injection process is repeated.

Based on empirical calculation using neutron detectors located outside the SURF facility, it is estimated that roughly 10E+11 neutrons per second are generated during the injection process.

However, the neutron flux is indistinguishable from background when the storage ring is operational. Concrete is used as shielding material in the room with walls up to 8 feet thick.

Section 3.0 Release Criteria The radiological release criteria of NRC 10CFR20 Subpart E for unrestricted use will be used for decommissioning the accelerator facilities. Specifically the buildings and facilities being released under this decommissioning effort will be surveyed in accordance with the guidance contained in MARSSIM to demonstrate compliance with the criteria specified in 10CFR20.1402 Radiological Criteria for Unrestricted Use. The specified criteria is that residual radioactivity results in a TEDE to an average member of the critical group that does not exceed 25 mrem per year and that the residual radioactivity has been released to levels that are as low as reasonably achievable (ALARA).

Default Screening Values The DCGL’s for the known radionuclides were determined using NUREG 1757 Vol.2, Table H- 1 or calculated using DandD v2.1.

Radionuclide Half-Life Radiation Type Default Screening Value (DPM/100 cm2)

Co-60 5.27 years Beta/Gamma 7.0E+03 Eu-152 13.54 years Beta/Gamma 1.27E+04

For situations where multiple radionuclides with their own DCGLs are present, a gross activity DCGL can be developed. This approach enables field measurement of gross activity, rather than determination of individual radionuclide activity, for comparison to the DCGL. The gross activity DCGL for surfaces with multiple radionuclides is calculated as follows:

(Equation 3-1) 1 2

1 2

Gross…